import aoclib
import math

DAY = 13
TEST_SOLUTION_PART1 = 295
TEST_SOLUTION_PART2 = 1068781


def part1(test_mode=False):
    my_input = aoclib.getInputAsArraySplit(day=DAY, split_char=",", test=test_mode)

    my_arrival = int(my_input[0][0])
    bus_ids = [int(i) for i in my_input[1] if i != 'x']
    waiting_times = [i - my_arrival % i for i in bus_ids]
    min_waiting_time = min(waiting_times)

    return min_waiting_time * bus_ids[waiting_times.index(min_waiting_time)]


def part2(test_mode=False):
    my_input = aoclib.getInputAsArraySplit(day=DAY, split_char=",", test=test_mode)

    bus_ids = {-i: int(v) for i, v in enumerate(my_input[1]) if v != 'x'}
    lowest_common_multiple = math.lcm(*bus_ids.values())
    base_multipliers = [lowest_common_multiple // interval for interval in bus_ids.values()]
    modular_multiplicative_inverses = [
        pow(base_multiplier, -1, interval)
        for base_multiplier, interval
        in zip(base_multipliers, bus_ids.values())
    ]

    return sum(
        offset * multiplier * mmi
        for offset, multiplier, mmi
        in zip(bus_ids.keys(), base_multipliers, modular_multiplicative_inverses)
    ) % lowest_common_multiple